The noise pollution caused by Berlin’s main traffic arteries was calculated for the forests and approx. 120 parks, allotment gardens and cemeteries.
For the calculation of the traffic noise pollution in the green and open spaces, the average daily traffic volumes (DTV) were taken as a basis on the main traffic arteries. As the statistical base, counts carried out by the Berlin Department of Transportation and Utilities of traffic volumes and proportions of truck traffic through 1992 were used.
In addition to the traffic figures, the following factors have entered in the calculation of the noise pollution:
- permissible maximum speed;
- surface and condition of the roadway;
- mean distance of the roadway from roadside developments;
- kind and mean amount of roadside development (open/closed development);
- traffic lights located at traffic crossings.
These data were ascertained in 1992 by on-the-spot investigations and evaluation of maps. In the eastern part of the city, streetcars were included in the calculation of the traffic noise pollution. The speed of the streetcars was assumed to average 50 km/h; for the frequency (streetcars per hour), schedules were consulted, and condition, composition and situation of the rail beds in the street area were determined by on-the-spot investigations and maps.
The data relevant likewise for the expansion conduct of noise over terrain elevations or molds and noise prevention walls were raised likewise by on-the-spot investigations and map evaluations.
No significant changes in the statistical base used for the map in 1992 are to be expected with regard to the noise pollution of the green and open spaces as a result of the new traffic count of 1993, although the traffic volume has increased. This is because only a considerable increase or decrease would change the pollution picture significantly. An increase or decrease of the traffic volume of 20%, for instance, would shift the isophones (lines of equal evaluation level) by only a few meters.